Changeset 8685

Timestamp:

05/21/07 23:41:22 (20 months ago)

Author:

alex

Message:

updates to improve the performance of _createNodesFromText. This checkins:

• replaces the cloning logic w/ direct node removal
  
• reuses the encapsulating node
  
• moves regular expression calculations out of the fast path and moves string trimming to the caching logic (verified that it's not called outside of this code path)
  
• hoists at least one invariant out of a loop (and this is regexp replacement, so it matters)
  
• moves "appendChild" logic for putting nodes in the rendered DOM to after the replacement of the innerHTML of the container
  

On the "themeTest.html" page, these changes reduced the time to construct the ~90 widgets on that page by nearly 20ms (112ms->93ms, avg).

Refs #3092

Files:

• dijit/trunk/base/TemplatedWidget.js (modified) (3 diffs)

dijit/trunk/base/TemplatedWidget.js

@@ -209 +209 @@
         }
 
+        templateString = templateString.replace(/^\s+|\s+$/g, "");
+
         if(templateString.match(/\$\{([^\}]+)\}/g)){
                 // there are variables in the template so all we can do is cache the string
@@ -248 +250 @@
 }
 
-dijit.base._createNodesFromText = function(/*String*/text){
-        //      summary
-        //      Attempts to create a set of nodes based on the structure of the passed text.
-
-        text = text.replace(/^\s+|\s+$/g, "");
-
-        var tn = dojo.doc.createElement("div");
-        tn.style.visibility="hidden";
-        dojo.body().appendChild(tn);
-        var tableType = "none";
+(function(){
         var tagMap = {
                 cell: {re: /^<t[dh][\s\r\n>]/i, pre: "<table><tbody><tr>", post: "</tr></tbody></table>"},
@@ -263 +256 @@
                 section: {re: /^<(thead|tbody|tfoot)[\s\r\n>]/i, pre: "<table>", post: "</table>"}
         };
-        for(var type in tagMap){
-                var map = tagMap[type];
-                if(map.re.test(text.replace(/^\s+/))){ //FIXME: replace with one arg?  is this a no-op?
-                        tableType = type;
-                        text = map.pre + text + map.post;
-                        break;
-                }
-        }
-
-        tn.innerHTML = text;
-        if(tn.normalize){
-                tn.normalize();
-        }
-
-        var tag = {cell: "tr", row: "tbody", section: "table"}[tableType];
-        var parent = tn;
-        if(typeof tag != "undefined"){
-                parent = tn.getElementsByTagName(tag)[0];
-        }
-
-        var nodes = [];
-        for(var x=0; x<parent.childNodes.length; x++){
-                nodes.push(parent.childNodes[x].cloneNode(true));
-        }
-//PORT  dojo.html.destroyNode(tn); FIXME: need code to prevent leaks and such
-        dojo.body().removeChild(tn);
-        return nodes;   //      Array
-}
+
+        var tn;
+        var _parent;
+
+        dijit.base._createNodesFromText = function(/*String*/text){
+                //      summary
+                //      Attempts to create a set of nodes based on the structure of the passed text.
+
+                if(!tn){
+                        _parent = tn = dojo.doc.createElement("div");
+                        tn.style.visibility="hidden";
+                }
+                var tableType = "none";
+                var rtext = text.replace(/^\s+/);
+                for(var type in tagMap){
+                        var map = tagMap[type];
+                        if(map.re.test(rtext)){ //FIXME: replace with one arg?  is this a no-op?
+                                tableType = type;
+                                text = map.pre + text + map.post;
+                                break;
+                        }
+                }
+
+                tn.innerHTML = text;
+                dojo.body().appendChild(tn);
+                if(tn.normalize){
+                        tn.normalize();
+                }
+
+                var tag = { cell: "tr", row: "tbody", section: "table" }[tableType];
+                if(typeof tag != "undefined"){
+                        _parent = tn.getElementsByTagName(tag)[0];
+                }
+
+                var nodes = [];
+                /*
+                for(var x=0; x<_parent.childNodes.length; x++){
+                        nodes.push(_parent.childNodes[x].cloneNode(true));
+                }
+                */
+                while(_parent.firstChild){
+                        nodes.push(_parent.removeChild(_parent.firstChild));
+                }
+                //PORT  dojo.html.destroyNode(tn); FIXME: need code to prevent leaks and such
+                _parent = dojo.body().removeChild(tn);
+                return nodes;   //      Array
+        }
+})();
 
 // These arguments can be specified for widgets which are used in templates.